FIGS. 1A–1C illustrate a conventional cushion ring sprocket S as is well known by those of ordinary skill in the art. The sprocket S comprises an annular member or portion M comprising a plurality of circumferentially spaced-apart teeth T projecting radially outward therefrom. The teeth T are separated by tooth spaces TS. The teeth T engage an associated chain (not shown). The sprocket S finds particular application in automotive engine timing and/or balance systems.
The sprocket S further comprises a hub H connected to or defined as a one-piece construction with the annular toothed portion M. First and second portions H1,H2 of the hub H project axially outwardly from the opposite first and second axial faces F1,F2 of the annular portion M (see FIGS. 1B and 1C). The first and second hub portions H1,H2 include or define respective cylindrical outer diameters OD1,OD2. As noted, the hub H and annular portion M can be assembled from separate structures or can be defined as a one-piece construction. The annular toothed portion M and hub H together define a sprocket body B that rotates about an axis of rotation X. A recess or through-bore C is defined in the hub about the axis of rotation X. The recess or bore C receives a shaft or other member that rotates with or rotatably supports the sprocket body B. The sprocket body B is typically defined from a suitable metal by casting, machining, powdered metal forming techniques or any other suitable means or material.
First and second circular cushion rings R1,R2 are provided and are loosely received on the respective cylindrical outer diameters OD1,OD2 of hub portions H1,H2, i.e., the cushion rings R1,R2 define inner diameters ID1,ID2 that are larger than the outer diameters OD1,OD2 on which the rings are received so that the rings R1,R2 can eccentrically float on the outer diameters OD1,OD2.
The cushion rings R1,R2 are movably captured or trapped on the hub portions H1,H2 by radially enlarged flanges G1,G2 that are fastened, welded or otherwise connected to the hub portions H1,H2, respectively. The flanges G1,G2 define respective circular outer diameters OG1,OG2 that are larger than the cushion ring inner diameters ID1,ID2 so as to trap the cushion rings loosely between the faces F1,F2 and flanges G1,G2, respectively.
The cushion rings R1,R2 are typically made from metal and, in use, are contacted by chain links of an associated chain (not shown) engaged with the sprocket teeth T. In use, the cushion rings R1,R2 eccentrically float on the hub outer diameters OD1,OD2 under force of the chain links and act to buffer or soften the impact of the associated chain with the sprocket S which leads to a decrease on noise.
These conventional cushion ring sprockets have been found to be highly effective. One drawback, however, is the relatively complex and time-consuming assembly process insofar as it relates to the installation of the cushion rings R1,R2 and the connection of the flanges G1,G2 to the hub portions H1,H2. In light of the foregoing, a need has been identified for the cushion ring sprocket and installation method disclosed hereinbelow.